In U.S. Pat. No. 3,567,418, issued to H. Hoette on Mar. 2, 1971, the disclosure of which is incorporated herein by reference in its entirety, there is shown a mechanism for mounting a straight-line shear frame underneath a feeder spout. According to this patent, the mounting mechanism permits the shear frame, and its associated shear mechanism, to be swung in a horizontal plane from its active position underneath the feeder outlet to an inactive position out from underneath the feeder orifice. This is desirable when it is necessary to provide maintenance service to the shear mechanism such as changing the shear blades, or when it is desirable to change the orifice ring in the feeder spout. In addition, in the device shown in the Hoette U.S. Pat. No. 3,567,418, the shear frame mounting mechanism provides a means for vertically adjusting the shear frame so that the shear mechanism therein can be positioned in a vertical direction different distances from the feeder orifice. Further, the mechanism disclosed in this patent includes means for releasably clamping the shear frame in its active position under the feeder spout orifice.
In the process of shearing glass gobs from a column of glass delivered to the shearing mechanism by the feeder through the feeder orifice, it is important to the formation of good gobs that the center line of each set of shear blades in a horizontal plane pass through the center line of the orifice in the orifice ring with which each set is associated. Also, the point of overlap of each set of shear blades should coincide as closely as possible with the center line of the associated orifice in the orifice ring through which the glass column issues. Due to tolerances required to manufacture and assemble the various parts of the spout and orifice ring and its support, the actual location of the center line of an orifice in the orifice ring may vary from the theoretical center line location. Additionally, the tolerances required in the manufacture and assembly of the shear assembly, shear frame, and mounting mechanism may result in the point of overlap of the shear blades not being completely in line with the center line of the orifices. Furthermore, when an orifice ring is changed because of wear or the need for different size due to a job change, the orifice center line may change to a different location. It is also desirable that the axis of shear blade travel is maintained perpendicular to the glass column being sheared to prevent tilting or distortion of the gobs.